The ultimate objective of any system for reproducing recorded music is to produce sound which to the listener is indistinguishable from a live performance.
When a person listens to a live performance of a musical work in, for example, a concert hall, he is subjected to a wealth and variety of sounds, some of which travel directly to the listener from the performers and others of which reach the listener through a profusion of reflections and reverberations within the hall itself. This fullness, or richness, of sound which one experiences from a live performance is usually missing from the home reproduction systems.
The sophisticated recording apparatus in use today are in large measure, capable of "catching" all the nuances of sound emanating from a live performance and some of the records in use today are capable of holding and generating electrical signals corresponding to that quality of sound. However, most home sound reproduction systems which are affordable by the average individual are not capable of reproducing the live performance sounds. This is true even through the home systems are frequently equipped with a multiplicity of speakers specially adapted to reproduce sounds in the low, mid and high frequency ranges exhibited by most musical compositions. Most home systems in use today are also capable of reproducing two channel, or stereophonic, sound and some are even capable of quadraphonic reproduction.
It has been recognized in the past that the practice of placing several speakers of different frequency ranges in a single cabinet or enclosure and mounted on a single baffle board in such a manner that all the speakers in the system are aimed generally at the listener inherently limits the quality of sound which the listener perceives. The sound reproduced by such systems are perceived by the listener as coming from either a point source within each of the speaker enclosures or a wall, or plane, containing the speakers. The listener perceives that the sound is being directed at him rather than surrounding him as often is the case in the live performance.
In efforts to get away from this point or wall source of sound, prior inventors have resorted to displacing the speakers in the system physically with respect to each other and reorienting the speakers so that they direct the sound in various directions. At least in theory, some of these systems are intended to produce non-directional, or omni-directional, sound more like a live performance.
U.S. Pat. No. 3,054,856 granted Sept. 18, 1962 to D. Arany for "Sound Reproducing System" discloses a system in which several speakers are redirected within an enclosure in an attempt to obtain "non-directional" emission of sound. This system utilizes a pair of low frequency range, or woofer, speakers disposed in the ends of a closed chamber in such a manner that the speakers are directed at each other. These speakers are electrically connected in such a manner that they vibrate in the same direction in response to a signal. In other words, they are arranged in a push-pull arrangement. Several high frequency range, or tweeter, speakers are disposed in the chamber intermediate the woofer speakers and directed radially outwardly in four quadrants of the chamber.
The Arany patent represents that the low frequency range speaker disposition there employed has the effect of accentuating the low frequency radiation and because the sound emanates from the rear, or convex side, of these speakers, instead of the more conventional direction from the concave side of the speakers the sound is sent out evenly in all directions without the directional remission of a typical commercial installation. So far as is known, this sound reproduction system has achieved no measureable listener recognition nor any commercial success.
U.S. Pat. No. 4,006,311 granted Feb. 1, 1977 to S. Carlsson for "Stereophonic Sound Reproducing Apparatus" discloses another sound reproducing system in which the low, mid and high frequency range speakers are oriented in different directions in an attempt to achieve an omni-directional reproduction of sound. The basic principle underlying this system is the recognition that there should be a certain ratio between the quantity of sound passing directly to the listener and the quantity of sound reflecting off the walls of the listening room. To this end, the speakers are oriented in such a manner as to direct sound therefrom at specific angles to adjoining walls of the room. The disadvantage of such a system, even if practical, is that for proper operation the speaker enclosure or enclosures must be strategically placed with respect to the walls of the room and with respect to the listener, thereby greatly reducing the versatility of such a system.
U.S. Pat. No. 4,199,657 granted Apr. 22, 1980 to H. Lane for "Planar Sound Reproducing Speaker System" purports to solve a resonance problem existing in conventional sound reproducing systems having more than one speaker within one cabinet. Lane proposes disposing several high frequency range speakers in individual cabinets supported by tubular members sticking out of the side walls of another cabinet carrying the mid range speaker. This combination of high and mid range speakers is supported on another post having a stand isolated from a cabinet housing the low frequency range speaker. This system has also failed to receive any critical appreciation from discriminating listeners.